A novel series of 2,6,7-substituted 2,3-dihydro-1,4-benzodioxin and 2,6,7-substituted 1,4-benzodioxin derivatives as lipid peroxidation inhibitors. Structure-activity relationships for high inhibition of human low-density lipoprotein peroxidation.

A series of 6- or 7-substituted 2-carboxamido- or 2-(aminomethyl)-1,4-benzodioxin and -2,3-dihydro-1,4-benzodioxin derivatives were synthesized and evaluated to determine the necessary structural requirements for a high inhibition of human low-density lipoprotein copper-induced peroxidation. The most active compounds (21, 25, 28, 36, and 37) were found between 5 and >45 times more active than probucol itself. Due to both their potency and their structural features, compounds 25 and 36 were selected with others for complementary in vitro and in vivo investigations. Both of them exhibit calcium antagonist properties in the same range of potency as flunarizine itself. Compound 36 was also found to have significant hypolipaemic activity in mice at 100 and 300 mg/kg po, while compound 25 proved to be clearly active in a normobar hypoxia test.

Effect of ethyl esterification of phenolic acids on low-density lipoprotein oxidation.

Inhibition of copper-induced low-density lipoprotein (LDL) oxidation by phenolic acids and their ethyl esters was investigated. LDL oxidation was evaluated by the hydroperoxide concentration and the chromatographic pattern of apoprotein fractions after fast protein liquid chromatography (FPLC). Antiradical properties against 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical and 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) were also investigated, and lipophilicity determined by thin-layer chromatography. Caffeic acid at 5 microM and sinapic acid at 10 microM protected LDL against oxidation, inhibiting both hydroperoxide formation and the increase of apoprotein negative charge. Ferulic, gallic and p-hydroxy cinnamic acids were ineffective. Ethyl esterification increased the lipophilicity of the five acids, and enhanced the antioxidant properties of caffeic, sinapic and ferulic acids. Ethyl caffeate was protective at 1 microM. In contrast, gallic and p-hydroxy cinnamic ethyl esters were ineffective. Our results indicate that ethyl esterification of phenolic acids increases lipophilicity of their ethyl esters and may enable a better incorporation into the lipid layer of the LDL particle and the exertion of their antioxidant effect in the true site of lipoperoxidation. However, increasing lipophilicity is not the only mechanism able to potentiate preexisting antioxidant properties of molecules, and probably other mechanisms are implicated.

[Refinement and role of the diagnosis of Gilbert disease with molecular biology]. / Mise au point et intérêt du diagnostic de la maladie de Gilbert par biologie moléculaire.

Gilbert syndrome (GS), characterized by mild, chronic and isolated unconjugated hyperbilirubinemia is due to a partial deficiency of bilirubin-UDP-glucuronosyltransferase (UGT1A1). Recently, the genetic basis of GS has been identified in caucasian populations : it is related to the insertion of a dinucleotide (TA) in the promoter region of the UGT1A1 gene. In Asian populations, GS is due to missense mutations (either homozygous or heterozygous) in the coding sequence. The aim of this study was to develop a simple and rapid method to detect both genetic polymorphisms and mutations. This technique was performed (1) to explore unrelated unconjugated hyperbilirubinemia; (2) to evaluate the frequency of GS in a population of 97 healthy caucasian volunteers: 17% of them were homozygous for the TA7/TA7 polymorphism; (3) to determine the incidence of this syndrome in a population of 105 neonates with unconjugated hyperbilirubinemia. The incidence of GS (15%) was not significantly higher than it was in the control group. A correlation between GS genotype and neonatal jaundice was not established; (4) to seek a relationship between GS and preeclampsia with or without Hellp syndrome. The incidence in the Hellp syndrome group (n = 19) was 26%, two fold higher than in preeclampsia group (n = 22) and control group (n = 50) with only 14% and 13% respectively, (5) to start a study regarding the toxicity of irinotecan treatment in a population of homozygous children for the UGT1A1 polymorphism.

Genetic heterogeneity of glycogen storage disease type Ia in France: a study of 48 patients.

Forty-eight patients with glycogen storage disease type Ia (GSD Ia) were studied. Using a combination of single-strand conformation polymorphism (SSCP) analysis, restriction enzyme digestion and direct sequencing, we were able to identify 93/96 mutant alleles, comprising 23 different mutations in the glucose-6-phosphatase gene (G6PC). Among these, 7 are novel mutations of G6PC: M5R, T111I, A241T, C270R, F322L, and two deletions, 793delG and 872delC, resulting in the same mutation at the amino acid level, fs300Ter (300X).

Apolipoprotein E polymorphism and serum concentrations in patients with glycogen storage disease type Ia.

In patients with glycogen storage disease type Ia (glucose-6-phosphatase deficiency), serum triglyceride concentrations are markedly raised, whereas phospholipids and cholesterol levels are only moderately elevated. In addition, both VLDL and LDL lipoprotein fractions are raised. Despite these abnormalities, endothelial vascular dysfunction and atherosclerosis seem to be rare in such patients. In view of the crucial role of apolipoprotein E (apoE) in lipid metabolism, we studied both apoE polymorphism (40 patients) and serum concentration (20 patients) in patients with glycogen storage disease type Ia. The distribution of each allele at the apoE locus was similar to that reported in the general population, whereas serum apoE concentrations were raised in our patients. Raised apoE levels in the serum could play an important role in counterbalancing the at-risk-for-atherosclerosis lipid profile of patients with glycogen storage disease type Ia. Moreover, E3 and E4 polymorphisms, predominant in our patients, have a high triglyceride binding capacity and are thus able to increase triglyceride clearance. However, the origin of raised concentrations of apoE is not completely clear though, bearing in mind previous reports regarding serum protein concentrations in such patients, increased hepatic synthesis is likely.

In vitro study of the cytotoxicity of isolated oxidized lipid low-density lipoproteins fractions in human endothelial cells: relationship with the glutathione status and cell morphology.

Toxic effects of oxidized lipid compounds contained in oxidized LDL to endothelial cells are involved in the pathogenesis of atherosclerosis. Glutathione (GSH) plays an important role in the redox status of the cell and in the protective effect against oxidant injuries. However, little is known about the respective effect of these different oxidized lipid compounds toward cytotoxicity and GSH status of the cell. In this report, we isolated by high-performance liquid chromatography oxidized lipid compounds from low-density lipoproteins (LDL) oxidized by copper and we examined their effects on cultured endothelial cells. Cytotoxicity and GSH status were determined after incubation of endothelial cells with crude LDL or isolated lipid fractions derived from cholesterol, phospholipids, or cholesteryl esters. Their effects on cell morphology were also assessed. Oxidized lipids coming from cholesteryl esters (hydroperoxides or short-chain polar derivatives) induced a slight but significant GSH depletion without inducing cytotoxicity. The same species coming from phospholipids induced a more pronounced GSH depletion and a cytotoxic effect which is only present for the more polar compounds (short-chain polar derivatives) and corresponding to a total GSH depletion. In contrast, fractions containing oxysterols had a larger cytotoxic effect than their effect on GSH depletion suggesting that their cytotoxic effects are mediated by a GSH-independent pathway. All together, these data suggest that LDL-associated oxidized lipids present in copper-oxidized LDL exert cytotoxicity by an additional or synergistic effect on GSH depletion, but also by another mechanism independent of the redox status of the cell.

[A new technique for measuring 17beta-estradiol using Kryptor (Cis Bio International): utilization to monitor ovulation stimulation]. / Une nouvelle technique de dosage du 17beta-estradiol sur le Kryptor (Cis Bio international): utilisation au cours des cycles stimulés.

We studied the performances of the 17b-estradiol determination with the Kryptor System (Cis Bio international), in assisted medical procreation cycles. The detection is based on Trace technology. We compared this method with Estradiol-6 method on ACS-180 (Bayer Diagnostics). The Kryptor method is sensitive, has a good precision and accuracy. Comparison with ACS-180 showed a good correlation but results were much higher. Patients under stimulation for assisted procreation were followed by the two methods. The results were close to those obtained with ACS-180 but significantly higher. Thus it was necessary to define the levels which have to be reached before ovulation induction.

Implication of apolipoprotein E and the L-arginine-nitric oxide system in preeclampsia.

OBJECTIVE: During pregnancy, Apolipoprotein (Apo) E is synthesized in the placenta to facilitate the uptake of maternal lipoproteins. Preeclampsia is associated with an abnormal lipid profile. Apo E levels may affect the production of nitric oxide. We investigated whether Apo E variations could be related to the high lipid levels and nitric oxide secretion in preeclamptic women. METHODS: Blood samples from 15 normotensive women and 12 mild and 23 severe cases of preeclampsia were assayed for standard lipid profile, Apo E, and nitrate. Urine samples were analyzed for nitrate and cyclic GMP. RESULTS: In women with mild preeclampsia, the triglyceride concentration was significantly higher (p < 0.05) than in normotensive women (3.30 +/- 1.38 versus 2.31 +/- 0.92 g/L) and associated with a higher (p < 0.01) triglyceride/Apo E ratio (0.71; range = 0.40-1.70). In women with severe preeclampsia, the triglyceride/Apo E ratio was similar to normotensive women [0.39 (range = 0.18-1.19) versus 0.41 (range = 0.18-0.79)] associated with a normal triglyceride level and a twofold higher serum nitrate level [36 (range = 1-63 mumol/L) versus 14 (range = 1-37 mumol/L)]. CONCLUSION: The triglyceride/Apo E ratio is significantly higher in mild preeclampsia. In the severe form, this ratio is similar to that of normotensive pregnant women, probably due to a better uptake of triglyceride. Moreover, in the severe form, it is associated with a twofold normal serum nitrate level. Thus, Apo E and the nitric oxide status may be implicated in preeclampsia.

Oxidized-LDL induce apoptosis in HUVEC but not in the endothelial cell line EA.hy 926.

We studied the cytotoxic effect of copper-oxidized LDL in human primary human umbilical vein endothelial cells (HUVEC) and the immortalized EA.hy 926 cell line. Copper oxidized LDL (50-200 microg apoB/ml) induced concentration-dependent apoptotic cell death in HUVEC but did not induce apoptosis in EA.hy 926 cells. Only necrotic EA.hy 926 cells were evidenced at all copper oxidized LDL concentrations (25-200 microg apoB/ml), oxidation states (lightly, moderately and extensively copper-oxidized LDL) and incubation periods (4, 8 and 20 h). The different mechanisms of cell death induced by copper-oxidized LDL in EA.hy 926 cells and HUVEC may be related to various factors such as cytokines. In this study, we investigated whether interleukin-8 may be implicated in this process. The interleukin-8 production was increased in EA.hy 926 cells but not in HUVEC incubated with oxidized LDL. This increase in EA.hy 926 cells was associated with necrosis but not apoptosis. Nevertheless, the addition of interleukin-8 to HUVEC did not inhibit apoptosis induced by oxidized LDL. As the lower antioxidant capacity of EA.hy 926 cells results in higher sensitivity to oxidized LDL cytotoxicity (as we previously described), the redox status of cells may also control the form of endothelial cell death. In atherosclerotic lesions, the formation of apoptotic endothelial cells may result in part from the induction by oxidized LDL.

Jaundice with hypertrophic pyloric stenosis as an early manifestation of Gilbert syndrome.

Jaundice associated with hypertrophic pyloric stenosis was recognised in three patients; previous reports have suggested that this is a possible early manifestation of Gilbert syndrome. Most patients with Gilbert syndrome are homozygous for a (TA)(7)TAA polymorphism in the gene promoter coding for bilirubin glucuronosyltransferase. Two of the reported patients were homozygous for the (TA)(7)TAA polymorphism whereas the third was heterozygous for the same polymorphism. Furthermore, no other factors contributing to jaundice in the three patients were found. These results suggest that jaundice associated with hypertrophic pyloric stenosis is due to molecular defects within the gene promoter.

Efficiency of ultrasound and biochemical markers for Down's syndrome risk screening. A prospective study.

OBJECTIVE: To evaluate the sequential combination of ultrasound screening for fetal aneuploidy at 11-14 weeks with maternal biochemistry at 12-14 and 15-18 weeks of gestation. METHODS: A prospective study including 1,656 women, with a singleton pregnancy booked before 13 weeks of gestation. Nuchal translucency (NT) thickness was measured by transabdominal ultrasound examination. alpha-Fetoprotein, free betahCG and hCG were measured by immunoradiometric (12-14 weeks) or immunometric (15-18 weeks) assays. Derived risks were then calculated. Cutoff risks were chosen first arbitrarily at 1/250 and then adjusted for a 5% false-positive rate. RESULTS: Seven fetal aneuploidies were diagnosed, including 5 Down's syndromes, 1 trisomy 18 and 1 triploidy. Three Down's syndromes had concordant high risk with the 3 screenings. One was at low risk with NT, and another was at low risk by maternal serum screening, but sequential combination of screenings led to a 100% detection rate with cutoffs of 1/240, 1/160 and 1/250 for NT, first- and second-trimester biochemistry, respectively (i.e. for a cutoff adjusted for a 5% false-positive rate). CONCLUSION: This preliminary study suggests a benefit in combining maternal age-related risk together with NT and biochemical markers in the first or the second trimester. The algorithm combining these risks needs to be established in a wide population.

Prenatal diagnosis of glycogen storage disease type Ia by restriction enzyme digestion.

Glycogen storage disease type Ia (GSD Ia) is an autosomal recessive condition, caused by a deficiency of hepatic glucose-6-phosphatase (G6Pase) activity. In a consanguineous family originating from northern Africa whose first daughter was affected with GSD Ia, we were able to identify the disease-causing mutation, a cytosine to thymine substitution at nucleotide 326 in exon 2 of the G6Pase gene (R83C). This mutation causes the disappearance of an HgaI site, and is thus easily detectable by restriction enzyme digestion. Both parents were heterozygous for this mutation. During the third pregnancy, fetal genomic DNA was extracted from a chorionic villus biopsy sampled at the 24th week of gestation. Exons 2 of the G6Pase gene were amplified by the polymerase chain reaction followed by HgaI digestion. Fetal DNA analysis indicated that the fetus had received both normal G6Pase alleles. This result was confirmed after birth. DNA analysis is the only reliable method for prenatal diagnosis of GSD Ia.

Urinary cGMP concentrations in severe primary pulmonary hypertension.

BACKGROUND: Prognostic evaluation of patients with primary pulmonary hypertension (PPH) requires right heart catheterisation. The development of accurate non-invasive methods for monitoring these patients remains an important task. Cyclic guanosine monophosphate (cGMP) is an indicator of the action of natriuretic peptides and nitric oxide on target cells. Plasma and urinary cGMP concentrations are raised in patients with congestive heart failure in whom they correlate closely with haemodynamic parameters and disease severity. The aim of the present study was to determine whether the urinary concentration of cGMP could be used as a non-invasive marker of haemodynamic impairment in patients with severe PPH. METHODS: Urinary cGMP concentrations were measured in 19 consecutive patients with PPH, seven with acute asthma, and 30 normal healthy controls. RESULTS: Patients with PPH had higher urinary cGMP concentrations than asthmatic patients or normal healthy controls (p = 0.001). Urinary cGMP concentrations were higher in patients with severe haemodynamic impairment--that is, those with a cardiac index (CI) of < or = 2 l/min/m2 (p = 0.002)--and urinary cGMP concentrations were inversely correlated with CI (r = -0.69, p = 0.002) and venous oxygen saturation (r = -0.65, p = 0.003). CONCLUSION: Urinary cGMP concentrations may represent a non-invasive indicator of the haemodynamic status of patients with severe PPH.

Influence of endothelial cells on structure, biochemistry and functionality of epidermis reconstructed on synthetic porous membrane.

The model of keratinocytes cultured on a synthetic porous membrane at the air-liquid interface leads to the formation of a pluristratified and cornified epidermis with histological and biochemical characteristics near those observed in vivo. In the present study, we evaluated the effect of proliferative endothelial cells on epidermalization. Keratinocytes were grown in three culture conditions: in defined medium (DM; control), in medium previously conditioned by proliferative endothelial cells (CM) and in medium with proliferative endothelial cells (pEC). The structures of reconstructed epidermis were analyzed by electron microscopy, their biochemistry by DNA, protein and cytokine analyses and finally their functionality was evaluated by estradiol and water absorption testing. Ultrastructural analysis showed a well-developed and cornified epidermis for each culture condition. In addition, living epidermis was thinner in the presence of endothelial cells, revealing faster epidermal differentiation. DNA and protein analyses were in accordance with these results. Secreted soluble factors varied according to culture conditions. At 37 degreesC, the permeability of reconstructed epidermis in DM, in CM or with pEC was 5- to 10-fold higher than that of native human epidermis with both tracers. Laminin coating of the inserts led to similar absorption results except for the DM where the barrier function to estradiol was decreased 2-fold. At 32 degreesC, reconstructed and native epidermis were, respectively, 1.5- and 2-fold less permeable to estradiol compared to 37 degreesC. In conclusion, this model is adequate for fundamental and pharmacological studies since it allows the study of interactions between two cell types without their direct contact as well as percutaneous absorption tests directly performed in the modified culture chamber.

Protective effects of the lipophilic redox conjugate tocopheryl succinyl-ethyl ferulate on HIV replication.

Previously, we demonstrated that ferulate ethyl and tocopherol reduced HIV replication. In this study, we investigate whether the conjugation of both compounds (O-tocopheryl succinyl O-ethyl ferulate) can increase HIV inhibition. We show here for the first time that O-tocopheryl succinyl O-ethyl ferulate inhibits 80% of HIV replication (HIV-1 acute infection and HIV transmission), inhibits cell lipoperoxidation and prevents cellular glutathione consumption. Compared to ferulate ethyl and tocopheryl succinyl, O-tocopheryl succinyl O-ethyl ferulate inhibits more HIV replication. This may be due in part to the great increase in the lipophilicity of this compound.

Comparison of oxidized low-density lipoprotein toxicity on EA.hy 926 cells and human vein endothelial cells: influence of antioxidant systems.

We compared the susceptibility to oxidized LDL cytotoxicity of primary human umbilical vein endothelial cells (HUVEC) and EA.hy 926 cells. EA.hy 926 endothelial cells were more susceptible than HUVEC. To determine the basis of this difference, we evaluated the enzymatic antioxidant machinery in the two cell types. The antioxidant enzyme activities of superoxide dismutase, catalase and glutathione peroxidase were significantly lower in EA.hy cells than in HUVEC: 54%, 71% and 8% of the HUVEC enzyme activities respectively. Pre-incubation of the EA.hy 926 endothelial cells with glutathione peroxidase (100 IU/ml) inhibited the cytotoxic effect of oxidized LDL. Superoxide dismutase (300 or 600 IU/ml) and catalase (300 or 600 IU/ml) had no effect. Compared to HUVEC, the higher susceptibility of EA.hy 926 cells to oxidized LDL induced injury may be associated with lower antioxidant defences, in particular with lower glutathione peroxidase activity which is known to eliminate lipid hydroperoxides and thereby to prevent the formation of damaging peroxyl radical intermediates.